Heating, ventilation, and/or air conditioning (HVAC) systems with thermostats may be used to control the indoor temperature of buildings. HVAC systems may be controlled by settings for heating, ventilation, cooling, humidity, and air quality. Typically, the thermostat provides a signal to another HVAC component to activate the component when a temperature passes a threshold temperature setting. The thermostat may provide power to a relay that turns on or off power to an HVAC component. The thermostat may provide a signal which is an alternating current (AC) signal. The power provided to the HVAC component may be AC power.